<template>
  <div class="ball">
    <!-- 模拟商品区域 -->
    <ul>
      <li v-for="(item, index) in 5" :key="index">
        <span @click="addCar">+</span>
      </li>
    </ul>
    <!-- 模拟购物车区域 -->
    <div class="shopCar" ref="shopCar">{{ number }}</div>
  </div>
</template>

<script>
export default {
  name: 'ball',
  data() {
    return {
      number: 0,
    };
  },
  mounted() {},

  methods: {
    /* 点击添加小球事件 */
    addCar(event) {
      let x = event.pageX - event.target.offsetWidth / 2;
      let y = event.pageY - event.target.offsetWidth / 2;
			console.log(x,y);
      this.createBall(x, y);
    },

    /* 创建小球，添加动画 */
    createBall(left, top) {
      let bar = document.createElement('div');
      bar.style.position = 'absolute';
      bar.style.left = left + 'px';
      bar.style.top = top + 'px';
      bar.style.width = '20px';
      bar.style.height = '20px';
      bar.style.borderRadius = '50%';
      bar.style.backgroundColor = '#02b6fd';
      bar.style.transition =
        'left .6s linear, top .6s cubic-bezier(0.5, -0.5, 1, 1)';

      document.body.appendChild(bar);
      // 添加动画属性
      setTimeout(() => {
        let target = this.$refs.shopCar;
        bar.style.left = target.offsetLeft + target.offsetWidth / 2 + 'px';
        bar.style.top = target.offsetTop + 'px';
      }, 0);

      this.number++;
      /**
       * 动画结束后，删除自己
       */
      bar.ontransitionend = function () {
        this.remove();
      };
    },
  },
};
</script>

<style lang="scss" scoped>
.ball {
  width: 100%;
  height: 100vh;
  ul {
    width: 100%;
    li {
      width: 100%;
      display: flex;
      justify-content: end;
      padding: 10px;
      span {
        display: inline-block;
        width: 30px;
        height: 30px;
        border-radius: 50%;
        background-color: aqua;
        color: aliceblue;
        font-size: 20px;
        text-align: center;
        line-height: 30px;
      }
    }
  }
}

.shopCar {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background-color: red;
  position: fixed;
  left: 20px;
  bottom: 30px;
  text-align: center;
  line-height: 50px;
  color: white;
  font-size: 12px;
}
</style>
